Explanation #1 (Rashi): This means to ruin his field.

Question: Just the contrary! Farmers normally plant wheat one year and barley the next year, and when they plant for two consecutive years wheat or [two years] barley, it ruins [the field]!

Strengthening of question: It connotes like this in Bava Basra (57b) regarding one [witness] who said that he consumed wheat [from the field], and one said that he consumed barley, like the Rashbam explained there!

Explanation #2: Rather, one who wants that his field will be esteemed, as if he left it fallow for a year, for so it is normal to seed it one year and leave it fallow for a year, so it will return to its strength from what it weakened...

[To return it to its strength without leaving it fallow,] he plants wheat one year, and barley for a year.

This is why R. Shimon ben Gamliel forbids to plant barley when he said that he will plant wheat, for perhaps last year he planted barley.

If he plows a second time, there is no problem. R. Shimon ben Gamliel would not forbid.

Implied question: Yehoshua stipulated that they gather grass everywhere, like it says in Bava Kama (81a)!

Answer: There it discusses grass that is not proper for people, only for animals.

Support: This is why the Gemara did not mention Yerakos (vegetables). However, leeks, which people eat, are forbidden, unless it is in a flax field.

Explanation #1 (Rashi): The tree is planted in the land close to the border, and the roots lean to his neighbor's side. This is difficult.

Explanation #2: Rather, the tree truly stands on the border, which is of both of them, and the roots do not spread to one's land more than to the other's. However, the branches lean more to the land of one of them;

Rav said that what leans to here belongs to [the owner] here. Since the roots are equal in this one's like in this one's, we follow the branches;

The branches even with the border, they divide them, and the rest go entirely to the property to which they lean.

Shmuel said that they divide. We follow the roots, which are equal. Likewise, they [divide] the branches equally;

However, if it was planted entirely in the Reshus of one of them, and the branches lean to his friend's Reshus, R. Yochanan taught in Bava Basra (27b) that [the former] brings Bikurim from them and recites (Viduy Bikurim, in which he says "the land that You gave to me");

Yehoshua caused [Bnei Yisrael] to inherit Eretz Yisrael on this condition, that all the branches belong to the owner of the roots. Rav and Shmuel in our Sugya agree to this.

Explanation #2 (cont.): We ask [against Rav from a Beraisa that says that] if a tree stands on the border, they divide. We answer that it fills the entire border. Just like the roots are all on the border, also the branches.

"It bears fruits on one side" does not mean that the branches cross the border. Rather, there are Peros on one side more than on his friend's side;

One might have thought that they divide according to the length on the border. The Mishnah teaches that this is not so. They divide according to the width on the border.

Reference: Below (118b), a Mishnah says that if there are two gardens one above the other and vegetables in between, all agree that the roots belongs to [the owner of] the top garden, because they nurture from his garden;

However, the foliage, which is in the air of the bottom, according to R. Yehudah it is of [the owner of] the bottom garden, and according to R. Meir it is of the top one, for he says "the foliage depends on the trunk";

There, [the Gemara] rules like R. Shimon, who says that whatever the top one can stretch his hand and take is his. This is like R. Meir. The rest, presumably, he made it Hefker for the bottom one.

Assertion: Even according to Rav, who does not hold here that the foliage depends on the trunk, could hold like R. Meir;

Since there, all the roots are of the top one, it is proper to say that the foliage depends on the trunk, like also R. Yochanan says in Bava Basra;

Shmuel, who says here that they divide, could hold there like R. Yehudah, who does not say that the foliage depends on the trunk, because it is common to fill one's garden with earth, and make it even with his friend's garden. (Since he did not do so, we attribute the Peros to him.)

Also, there is no foliage in the Reshus of the top one. Immediately when it is seen out of the ground, it is in the Reshus of the bottom one;

Distinction: In our Sugya, most of the foliage is on the border. Only a little branches lean to here and to here, outside the width on the border.

Question: If so, Bnei Yosef, over whom Ayin ha'Ra does not rule, should live much longer than the other Shevatim!

Answer: They died through Derech Eretz more than the others, for when Hash-m wants to kill them, he sends them other illnesses.

Explanation: This is cold, like is proven here. Pachim is heat, like is proven in Avodah Zarah (3b);

Here we discuss occurrences that come upon a person;

Regarding Midos (natures, i.e. wise or foolish, strong or weak...) it says (Nidah 16b) that everything is in Shamayim's hand, except for fear of Heaven.

Explanation #1: It mentions 60, because there are 60 days of Choref (winter, in between seeding and Kor (cold)), and similarly 60 days of Kayitz (summer, in between harvest and Chom (heat)), like it says above (106b), and bread in the morning saves from heat and cold.

Explanation #2: The Gemara always mentions 60, like it says in Bava Kama (92b) that 60 pains befall the big teeth of one who hears another [eat, but he himself does not eat].

Explanation: The four Amos that you measure for people of Anigra, who draw [water] from there to irrigate their fields, disgrace [them]. I.e. measure them with smiling Amos (slightly more than exact Amos, for each Tefach is measured with spaces between the fingers), and not with exact Amos, so they can stand there with space.

This is unlike Rashi, who explained that by the river, they leave place also for people who pull ships. Do not measure it at all, for they need much room, lest they fall into the water;

Rather, give it without measuring. It should be overtly recognized [that it is at least four Amos].

Note: The Acharonim say that the coming Dibur is really part of this Dibur.

Explanation: Branches of trees of the forest - cut them, for (people pulling boats) must lean their shoulders to the side of the forest, lest they fall into the water.

Question: We say in Bava Basra (99b) that if one said "I sell to you an Amah (irrigation channel) of a Beis ha'Shelachin (irrigated field), he gives to him two Amos in it - an Amah on each bank!

Answer: There we discuss an Amah of one person. He makes a furrow in his field to irrigate from it, and one Amah on each side suffices for banks;

Here we discuss Anigra, which is a large river to irrigate the entire valley. Therefore, four Amos are needed for the banks

Support: There, we seed the Amos and plant trees there, like it says there, but here we do not seed and plant at all, for everyone goes there to irrigate their fields.

Implied question: Why does it say [here] that [the four Amos next to] the river is of everyone (but the four Amos of Anigra, disgrace them)?

Answer #1: This is not because all (four Amos of) Anigra is of one person. Rather, it is not of everyone. It is only for those who irrigate their fields.

Answer #2: The four Amos here are two Amos in it (the irrigation channel), and one Amah on each side.